Ovens that are self-cleaning are well known. Such self-cleaning ovens include a cleaning mode or cycle that is initiated by a user. The self-cleaning cycle generates intense heat inside the oven. The intense heat reduces food particles, grease, spills and splatter (collectively, build-up) inside the oven to ash. Once the cleaning cycle is complete, the resulting ash may then be easily wiped away.
Because of the intense heat necessary to reduce such build-up to ash, self-cleaning ovens lock the oven door during the cleaning cycle to prevent access thereto. Self-cleaning ovens thus include a locking mechanism that keeps the oven door shut and locked during the cleaning cycle. While the locking mechanism may be manually actuated, most locking mechanisms in current self-cleaning ovens are automatically actuated when the self-cleaning mode is selected.
Such locking mechanisms include a latch that is controlled by the motor. The latch cooperates with a lock jamb in the door of the oven to lock the door when the door is in a closed position. The latch, via the motor, creates a compressive force between the door and the oven. This seals the oven door against the oven. Tolerance stack-up on doors, frames and hinges of the oven uses up the compressibility of the seal of the door and can cause current locking mechanisms to undesirably stall.
Current oven designs thus cause oven manufacturers to want a locking mechanism that has high strength and low cost. Strength or force has also begun to be associated with the position of the latch with respect to the door lock jamb. Higher strength or force for the locking mechanism translates into a higher cost. In order to lower the price for such locking mechanisms, force requirements have been eroded. Since over half the cost of such locking mechanisms is in the gear motor, reducing force requirements reduces the size of the motor necessary to achieve the required force by the latch. As an example, the following table (Table 1) illustrates how such force requirements have been eroded.
TABLE 1DateStrokeDimension ToleranceForce7/980.8″0.075″12 lbs2/000.65″0.100″4 to 6 lbs4/000.54″0.090″3 to 4 lb
It is known art to drive or actuate the latch of the locking mechanism directly from the motor of the locking mechanism via lock levers. However, even with the reduction of force requirements and such direct drive mechanisms, the problem of stalling of the latch is still present.
In addition to providing a latching function, current locking mechanisms provide switches that control various aspects of the oven associated with or because of the self-cleaning mode. The switches in such current locking mechanisms are actuated via a radial (drum) cam that is driven by the motor. A radial or drum cam has a thickness or stack in proportion to the number of switches associated with the locking mechanism. A problem with such radial cams is that the thickness (height) of the drum stack would become too large to package the many switches that are now part of the locking mechanism in a convenient ganged array if the drum stack is too large, the locking mechanism becomes too thick for useful or practical packaging for ovens.
Therefore, each one of the many switches located on the locking mechanism requires two terminals (a set of terminals). Each set of terminals needs to be coupled to a controller or other component of the oven. Currently, each terminal of each set of terminals is connected to the controller or other component via an individual spade connector. During assembly, each spade connector must therefore be connected individually. This can present a problem of correctly connecting the various spade connectors.
What is therefore needed is a door locking mechanism for a self-cleaning oven that overcomes the disadvantages of the prior art. What is further needed is a door locking mechanism for a self-cleaning oven that is low cost, provides enough strength (force) for door closure retention, provides little or no stall, accommodates a plurality of switches, and is low-profile. What is therefore further needed is a door locking mechanism for a self-cleaning oven that can be retrofitted into existing self-cleaning oven models.